1. What is a Solar Panel Wattage Calculator?

Definition: This calculator determines the required solar panel wattage based on your energy needs, available sunlight hours, and system efficiency.

Purpose: It helps homeowners and solar installers properly size solar panel systems for optimal energy production.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Required solar panel wattage (watts)
• \( E_{kWh} \) — Daily energy consumption (kilowatt-hours)
• \( t_{sun} \) — Average daily peak sun hours
• \( \eta_{solar} \) — System efficiency factor (0-1)

Explanation: The energy need is converted to watt-hours, then divided by available sunlight hours and system efficiency to determine required panel wattage.

3. Importance of Proper Solar Panel Sizing

Details: Correct sizing ensures your solar system meets energy demands, maximizes return on investment, and prevents over/under-sizing issues.

4. Using the Calculator

Tips: Enter your daily energy usage in kWh, average peak sun hours for your location (default 4.5h), and system efficiency (default 0.75). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical sun hours for my area?
A: Sun hours range from 3-6 daily in most locations. Check solar maps for your specific region.

Q2: What affects system efficiency?
A: Factors include panel orientation, temperature, wiring losses, inverter efficiency, and shading (typically 70-85% total).

Q3: Should I round up the calculated wattage?
A: Yes, it's recommended to round up to the nearest standard panel size and add 10-20% buffer for optimal performance.

Q4: How do I find my daily energy usage?
A: Check your electricity bill for monthly kWh usage and divide by 30, or use an energy monitor.

Q5: Does this account for battery storage?
A: No, this calculates panel size for direct usage. For battery systems, you'll need additional calculations.